In John 19:10-11, Pilate is saying that he has to power to kill Jesus. This is not the case. Jesus came to the world to die. Jesus' life isn't in Pilate's hands, it's in God's hands, and God's will was for Jesus to die for the sins of the world. Does that mean that God is giving Pilate the power to do evil? First of all, death is the punishment of sin. If God kills someone, it is not evil, it is justice. If God let's someone live, it is not a lack of justice, it is a gracious gift. Of course, only God has the right to administer this justice. Jesus didn't sin, but He was still dying for sin. He was a willing sacrifice, meaning that He was to be judicially treated as the offender while those who believe would be justified by His death. God gave Pilate the authority to kill Jesus, and that authority is not evil but justice. Again, it was not justice for a crime that Jesus committed, but justice for our crimes.
Furthermore, God can restrain evil, or He can allow evil. God easily could have prevented Joseph from being sold into slavery, but he chose not to. God gave Joseph's brother the power to do that evil. God did not sin in letting Joseph's brothers sin. Instead, God chose to use for good what Joseph's brothers meant for evil.
Therefore, the one who delivered Jesus into the hands of Pilate did the greater sin. Pilate was God's instrument of justice. Judas was not. Pilate wanted justice. Judas wanted money.
As for Isaiah 45:7, the way I understand it is this: the Hebrew word for "evil" can also be translated "calamity." The NKJV says, "I form the light and create darkness, I make peace and create calamity; I, the LORD, do all these things." Basically, "evil" in this context has no more the meaning of moral evil as "peace" does of moral good. God creates peach in Israel as well as calamity. When Israel sinned, God created calamity for them in raising up a nation to take them captive. When Israel repented, God created peace for them in raising up Cyrus to send them back to their homeland (as is the context of this passage).
God defined good. Therefore, He also defined evil. In this way, God "created" evil, but no more than shining a light in a dark room creates shadow. Saying God is the ultimate source of evil is like saying a light is the ultimate source of darkness because it creates shadows. God can chose to allow one to commit an evil, as He allowed Joseph's brothers to commit evil, but that does not make Him the source of evil. Instead, God uses evil for good.